////////////////////////////////////////////////////////////////////////
TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5076
SUBJECT: GRB 060505: Swift-BAT detection of a weak burst
DATE: 06/05/05 20:35:05 GMT
FROM: Jay R. Cummings at NASA/GSFC/Swift
D. Palmer, J. Cummings, M. Stamatikos, C. Markwardt, T. Sakamoto
At 06:36:01 UT Swift-BAT triggered on GRB 060505 (Trigger #208654).
The onboard imaging detected a 6.4 sigma excess.
This is below our (6.5 sigma) threshold for ground notification
and automatic slew. Subsequent ground analysis imaged a different
selection of the data and found a convincing 8.5 sigma excess at
(RA, Dec) = 331.765, -27.819 {22h 07m 04s, -27d 49' 09s} (J2000)
The light curve shows a weak burst, ~1500 cts/sec (15-350 keV) 1 sec
after the trigger. T90 is ~4 seconds.
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TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5078
SUBJECT: GRB 060505: Swift XRT afterglow canditate position
DATE: 06/05/06 03:28:24 GMT
FROM: Milvia Capalbi at ISAC/ASDC
M.L. Conciatore, M. Capalbi, L. Vetere (ASDC), D. Palmer (LANL),
D. Burrows (PSU) report on behalf of the Swift/XRT team:
The Swift XRT began observing GRB 060505 field (trigger #208654,
Palmer et al., GCN 5076) at 20:58:25 UT, 14.37 h after the BAT trigger.
>From the analysis of the first 4 ks data set we find a faint source at
the following coordinates:
RA(J2000) = 22h 07m 03.2s
Dec(J2000) = -27d 48' 57"
with an estimated uncertainty of 5 arcseconds (90% containment). This
position lies 13.9 arcseconds from the center of the BAT error circle
reported in GCN 5076.
This source is 6.7 arcsec from the USNO star 0621-1164653 and 4.1
arcsec from the 2df galaxy S173Z112.
Due to the small number of counts, we are unable to determine whether
the source is decaying at this time. Observations are continuing and
further analysis regarding the fading nature of this source will be
issued as the data becomes available.
This circular is an official product of the Swift XRT Team.
////////////////////////////////////////////////////////////////////////
TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5081
SUBJECT: GRB 060505: Swift XRT Team Refined Analysis
DATE: 06/05/06 16:54:21 GMT
FROM: Maria Laura Conciatore at ASDC
M.L. Conciatore, M. Capalbi, L. Vetere (ASDC), L.A. Antonelli (INAF/OAR),
D. Palmer (LANL), D. Burrows (PSU) report on behalf of the Swift/XRT
team:
We analysed the first 8 ks XRT data from GRB 060505. We found two
detections whithin the BAT error circle (GCN 5076). The first source
already reported in GCN 5078 shows a constant flux of (1.1 +/- 0.1)e-2
counts/s and it is unlikely to be associated with the afterglow of GRB
060505. We also note that the 2df galaxy S173Z112 lays within the XRT
error circle (GCN 5078).
A very faint second source is located at:
RA(J2000) = 22h 07m 4.5s,
Dec(J2000) =-27d 49m 57.8s
with an uncertainty of 4.7 arcsec (90% containment). This position lies
63.2 arcseconds from the center of the BAT error circle reported in
GCN 5076. Due to the small number of counts (15 counts) we are unable
to determine whether the source is the possible afterglow candidate of
GRB 060505.
We note that the positions of both sources are also consistent with a
previously known ROSAT source (1WGA J2207.0-2749) error box (50 arcsec).
This Circular is an official product of the Swift XRT Team.
////////////////////////////////////////////////////////////////////////
TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5082
SUBJECT: GRB060505: Swift/UVOT Observations
DATE: 06/05/06 17:17:46 GMT
FROM: Peter Brown at PSU
P J. Brown (Penn State) & D. Palmer (LANL)
on behalf of the Swift/UVOT team.
The Swift/UVOT began observing the field of GRB060505
(BAT Trigger=208654, Palmer et. al, GCN 5076) at
2006-05-05 20:58:30 UT, 14.37 hours after the BAT trigger.
The galaxy at the position of the first XRT source
(Conciatore et al GCN 5078) is detected in all 6 filters
but does not show significant variation, consistent with
Conciatore et al (GCN 5081).
No source is detected at the position of the second XRT
source (Conciatore et al GCN 5081) in coadded images with
any of the filters. The following 5-sigma magnitude
upper limits are not corrected for Galactic extinction.
Filter T_range(h) T_exp(s) 5sigmaUpperLimit(mag)
V 14.85-19.73 835 19.1
B 14.56-19.44 835 20.2
U 14.49-19.38 835 19.9
UVW1 14.37-19.32 1666 19.8
UVM2 14.92-19.85 1987 20.1
UVW2 14.62-19.67 3388 21.0
Where T_range is time post-trigger in hours, and T_exp
is the exposure time of the summed image in seconds.
////////////////////////////////////////////////////////////////////////
TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5089
SUBJECT: GRB 060505: PROMPT Observations
DATE: 06/05/08 00:12:19 GMT
FROM: Josh Haislip at U.North Carolina
J. Haislip, M. Nysewander, D. Reichart, A. LaCluyze, J. A. Crain, K.
Ivarsen, A. Foster, C. MacLeod, J. Kirschbrown, A. Trotter, and J.
Carpenter report on behalf of the UNC team of the FUN GRB Collaboration:
Skynet observed the localization of GRB 060505 (Palmer et al., GCN 5076)
with three of the 16-inch PROMPT telescopes at CTIO beginning 23.2 hours
after the burst in Ug'r'i'z'. Two of these telescopes reobserved the field
in i'z' beginning 47.2 hours after the burst.
No new source is found to z' > 20.6 mag (3 sigma) at 25.5 hours after the
burst.
PROMPT is currently being built and commissioned.
////////////////////////////////////////////////////////////////////////
TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5114
SUBJECT: GRB 060505: X-ray afterglow
DATE: 06/05/11 15:35:56 GMT
FROM: Maria Laura Conciatore at ASDC
M.L. Conciatore, M. Capalbi, L. Vetere (ASDC), D. Palmer (LANL),
D. Burrows (PSU) report on behalf of the Swift/XRT team:
The Swift X-Ray Telescope observed the field of GRB 060505 (GCN 5076)
for a second time on 2006-05-10 from 00:43:58 UT for a total
exposure of 11.7 ks.
The source identified in the first observation (GCN 5078) located at:
RA(J2000) = 22h 07m 03.2s
Dec(J2000) = -27d 48' 57
has faded from (1.1 +/- 0.1)e-2 counts/s to
(8.6 +/- 4.0)e-4 cts/s.
The other source reported in GCN 5081, located at:
RA(J2000) = 22h 07m 4.5s,
Dec(J2000) =-27d 49m 57.8s
shows a constant behavior of the light curve, with a count rate of
about 2e-2 cts/s.
We conclude that the first source is the likely X-ray afterglow
of GRB 060505.
This Circular is an official product of the Swift XRT Team.
////////////////////////////////////////////////////////////////////////
TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5115
SUBJECT: GRB 060505: X-ray afterglow - Correction -
DATE: 06/05/11 16:41:45 GMT
FROM: Maria Laura Conciatore at ASDC
M.L. Conciatore (ASDC) report on behalf of the Swift/XRT team:
In GCN 5114, we incorrectly reported that count rate of the second
source (the constant one) was 2.e-2 cts/s. The correct value is 2.e-3
cts/s.
Please, find below the corrected GCN text.
========================================================================
M.L. Conciatore, M. Capalbi, L. Vetere (ASDC), D. Palmer (LANL),
D. Burrows (PSU) report on behalf of the Swift/XRT team:
The Swift X-Ray Telescope observed the field of GRB 060505 (GCN 5076)
for a second time on 2006-05-10 from 00:43:58 UT for a total exposure
of 11.7 ks.
The source identified in the first observation (GCN 5078) located at:
RA(J2000) = 22h 07m 03.2s
Dec(J2000) = -27d 48' 57
has faded from (1.1 +/- 0.1)e-2 counts/s to
(8.6 +/- 4.0)e-4 cts/s.
The other source reported in GCN 5081, located at:
RA(J2000) = 22h 07m 4.5s,
Dec(J2000) =-27d 49m 57.8s
shows a constant behavior of the light curve,
with a count rate ofabout 2e-3 cts/s.
We conclude that the first source is the likely X-ray afterglow
of GRB 060505.
This Circular is an official product of the Swift XRT Team.
////////////////////////////////////////////////////////////////////////
TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5123
SUBJECT: GRB 060505 - OT candidate + galaxy spectrum
DATE: 06/05/13 02:18:58 GMT
FROM: Eran Ofek at Tel Aviv U.
E. O. Ofek, S. B. Cenko, A. Gal-Yam (Caltech), B. Peterson, B. P.
Schmidt, (ANU), D. B. Fox (Penn State), and P. A. Price (IfA, Hawaii)
report on behalf of a larger collaboration:
We have imaged the region of the 4s-duration GRB060505 (GCNs 5076; 5078;
5114; 5115) with the GMOS instrument on the Gemini South Telescope, in g'
and r'-bands, on 2006 May 6.4 and on 2006 May 12.3.
Inspection of single g' and r'-band images from each night reveals the
presence of a variable source 4."3 from the z=0.089 galaxy 2dFGRS
S173Z112 (7kpc in projection). The afterglow coordinates are:
22:07:03.44 -27:48:51.9 (J2000.0)
relative to the USNO-A2.0 catalog.
The OT is found 6" from the nominal XRT coordinates
(which have 4."7 uncertainty, 90% confidence).
On 2006 May 6.40, the g'-band magnitude of the proposed afterglow was
g~21.5,
and on 2006 May 12.31 it was g'~22 (Compared to USNO-A2.0).
We further inspected the publicly available 2dF spectra
of the z=0.089 galaxy 2dFGRS S173Z112, found within the XRT error circle
of GRB 060505 (GCN 5078).
The spectra shows prominent emission lines of Halpha, Hbeta, OI, OII, OIII
and SII. In absorption we detect the G-band and the CaII H line (but not
the K line). The spectrum suggests this is a late type galaxy.
////////////////////////////////////////////////////////////////////////
TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5142
SUBJECT: GRB 060505 BAT refined analysis
DATE: 06/05/15 19:54:31 GMT
FROM: Jay R. Cummings at NASA/GSFC/Swift
D. Hullinger (BYU-Idaho), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), M. Koss (GSFC/UMD), C. Markwardt (GSFC/UMD),
D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU),
G. Sato (GSFC/JSPS/USRA), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), on behalf of the Swift-BAT team:
Using the data set from T-2 to T+8 sec, we report further analysis
of GRB 060505 (Palmer et al. GCN 5076). The refined ground-analysis
position is RA, Dec 331.776d, -27.825d (22h 07m 06.3s, -27d 49' 31")
+- 2.1 arcmin (J2000, estimated uncertainty, 90% containment). This
position is 0.6 arcmin from the XRT refined position reported by
Conciatore et al. in GCN 5081. The partial coding was 11%. As noted
earlier, this was a ground-discovered burst that did not trigger the
BAT instrument. Thus we have only a limited set of full-resolution
data.
The mask-weighted light curve shows a single rounded peak. T90 is
4 +- 1 sec (15-350 keV, estimated error including systematics).
The BAT counting rates give no indication of extended emission.
However, Swift was approaching the SAA and BAT entered SAA mode
with even more limited data collection at T+60, so constraints on
emission are poor.
The time-averaged spectrum is well fit by a simple powerlaw with
index 1.3 +- 0.3. The energy fluence in the 15-150 keV band is
6.2 +- 1.1 x 10^-7 ergs/cm2. The 1-second peak flux, also in the
15-150 keV band, from T+2 sec is 1.9 +- 0.3 ph/cm2/s. All the
quoted errors are at the 90% confidence level.
////////////////////////////////////////////////////////////////////////
TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5161
SUBJECT: GRB060505: VLT observations of the optical afterglow
DATE: 06/05/26 14:27:24 GMT
FROM: Christina Thoene at Niels Bohr Institute,DARK Cosmo Ctr
Christina C. Thoene, Johan P.U. Fynbo, Jesper Sollerman, Brian L. Jensen,
Jens Hjorth (Dark Cosmology Centre), Pall Jakobsson (Univ. of Hertfortshire),
Sylvio Klose (TLS Tautenburg) report on behalf of a larger collaboration:
We observed the OT position of GRB060505 (GCN 5123), with FORS2/VLT on May
23.28. Comparison with our FORS1/VLT images from May 5.41 shows that the
source has faded from R=21.3 on May 5.41 to R>23 on May 23.28.
At the position of the OT, we detect a bright, star-forming region in the
spiral arm of the possible host galaxy 2dFGRS S173Z112 with redshift
z=0.089 (GCN 5123). Spectroscopy with VLT/FORS2 confirms that this region
is part of the host galaxy. Therefore, it is possible that the source
reported in GCN 5123 for images taken on May 12th, might actually be the
underlying star-forming region.
The observations put a strong limit on the presence of an underlying SN
similar to SN 1998bw at redshift 0.089, which we would expect to have a
magnitude of R=18.4 at the time of our 2nd observation. Therefore, either
there is no associated SN, the SN is about 4 magnitudes fainter than SN
1998bw, it is strongly extinguished, or GRB060505 is not at z=0.089. The
strengths of the Balmer lines and the fact that the host galaxy is seen
close to face on argue against strong dust extinction.
We thank the Paranal staff, in particular Claudio Melo and Rachel Gilmour,
for excellent support.